Strutt, John William, Third Baron Rayleigh
Lord Rayleigh (as he is universally known in scientific circles) was one of the greatest ornaments of British science in the last half of the nineteenth century and the first two decades of the twentieth. A peer by inheritance, he took the unusual course of devoting himself to a scientific career and maintained his research activity continuously from the time of his graduation from Cambridge University in 1865 until almost literally the day of his death. Rayleigh’s investigations, reported in 430 scientific papers and his monumental two-volume treatise The Theory of Sound (1877–1878), covered every field of what in the twentieth century is commonly referred to as “classical” physics; at the same time he kept abreast of, and made incisive critical comments on, the latest developments of quantum and relativistic physics. Not in any sense a pure mathematician, Rayleigh applied mathematics with great skill and accuracy to a host of problems in theoretical physics. In addition he was an ingenious and resourceful experimentalist, with the uncanny ability to extract the most from the simplest arrangements of apparatus. The discovery and isolation of argon, usually considered by the lay public as his greatest scientific achievement, was a triumph of both careful logical reasoning and patient and painstaking experimentation.
At Cambridge, Strutt became a pupil of the mathematician E. J. Routh and profited greatly from his thorough coaching. This and the inspiration gained from the lectures of Sir George Stokes, at that time Lucasian professor of mathematics, paved the way in part at least for Strutt’s emergence as senior wrangler in the mathematical tripos as well as Smith’s Prizeman. He became a fellow of Trinity College, Cambridge, in 1866; and from that time on, there was no doubt that he was headed for a distinguished scientific career.
Figures & Tables
Classics of Elastic Wave Theory
In this chapter, we give a brief synopsis of each of the classic papers referred to in this collection. Where relevant, we reproduce the basic equations, recast in modern notation. Supporting works also are referred to. They are listed in the “General References” section.
Table 1 is a quick outline of the key contributions of each paper reprinted in this book.
Robert Hooke, “Potentia Restitutiva, or Spring” (Oxford, 1678)
The article by Robert Hooke, “Potentia Restitutiva, or Spring,” contains the statement of the proportional relation between stress and strain universally referred to as Hooke’s law. Although the English language has evolved somewhat since 1678, the article does not require translation. Hooke describes a variety of experiments, accompanied by illustrations, confirming the stress/strain relation over a wide range of applied loads. He emphasizes the great generality of his results.
Based on his experimental work from 1660 onward, Hooke first published his law in 1676 in the form of an anagram in Latin,
which he later revealed to be “ut tensio sic vis.” Roughly translated, this means “as the force, so is the displacement” (Love, 1911; Boyce and DiPrima, 1976).
In his treatise, Hooke examined the behavior of springs, so his first casting of the equations dealt with the restoring force on a spring, for a given displacement: